1. Field of the Invention
The present invention concerns a method and a device for positioning a patient support device (patient bed, patient table) in a magnetic resonance apparatus, in particular for positioning such a support device in a magnetic resonance apparatus in combination with one or more local coils of the magnetic resonance apparatus.
2. Description of the Prior Art
In the course of an imaging examination with a magnetic resonance apparatus, the subject to be examined (for example a patient) is first positioned in relation to the measurement center of the magnetic resonance apparatus. In order to avoid unnecessary and costly incorrect measurements, an optimally precise positioning is desirable.
In conventional magnetic resonance apparatuses, the patient is located on a patient bed which can be positioned within the magnetic resonance apparatus using a drive device that is controlled by a control device of the magnetic resonance apparatus. The position of the patient is communicated to the control device of the magnetic resonance apparatus by means of a light marker that is arranged remote and stationary at the magnetic resonance apparatus at a predetermined distance from the magnet center of the magnetic resonance apparatus. Operating personnel manually position the patient bed with the patient located thereon such that the region of the patient to be examined is marked by the light marker. As soon as this manual positioning is concluded, this is communicated to the system by a button press and the patient is automatically positioned in the magnetic resonance apparatus by the control device controlling the drive of the patient bed such that the region to be examined comes to be located in the magnet center.
Antennas known as local or surface coils are frequently used for more precise examination of specific regions (parts) of the patient. For example, these can be special coils for the head, the neck or the spine. These coils are attached on the patient bed and the patient is positioned on the patient bed such that the region of the patient to be examined is aligned to the coils. With the use of the light marker, positioning of the patient bed subsequently ensues in turn relative to the magnet center of the magnetic resonance apparatus. For this purpose, the housings of the local or surface coils have labels (targets) that are aligned on the light marker by operating personnel by manually-controlled movement of the patient bed.
This manually controlled alignment using the light marker requires a not insignificant amount of time. The patient throughput of the magnetic resonance apparatus is thereby reduced, and the work effort for the operating personnel is increased. Both lead to not insignificant costs in the operation of the magnetic resonance apparatus. Moreover, this not insignificant positioning time leads to problems in imaging methods that must be implemented particularly quickly, for example positron emission tomography (PET) examinations, in which the radiation of the substances administered to the patient decreases rapidly, and thus the imaging results become increasingly poorer with advancing time. Moreover, given PET methods the operating personnel should stay in proximity to the patient as briefly as possible in order to receive as low as possible a radiation dose from the patient.